2WLC

Crystallographic analysis of the polysialic acid O-acetyltransferase OatWY

2WLC の概要

• エントリーDOI: 10.2210/pdb2wlc/pdb
• 関連するPDBエントリー: 2WLD 2WLE 2WLF 2WLG
• 分子名称: POLYSIALIC ACID O-ACETYLTRANSFERASE, ACETATE ION, 1,2-ETHANEDIOL, ... (5 entities in total)
• 機能のキーワード: transferase, enzyme, acetyltransferase, left-handed beta helix
• 由来する生物種: NEISSERIA MENINGITIDIS SEROGROUP Y
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 24693.52

構造登録者

Lee, H.J.,Rakic, B.,Gilbert, M.,Wakarchuk, W.W.,Withers, S.G.,Strynadka, N.C.J. (登録日: 2009-06-23, 公開日: 2009-06-30, 最終更新日: 2024-05-01)

主引用文献

Lee, H.J.,Rakic, B.,Gilbert, M.,Wakarchuk, W.W.,Withers, S.G.,Strynadka, N.C.J.
Structural and Kinetic Characterizations of the Polysialic Acid O-Acetyltransferase Oatwy from Neisseria Meningitidis.
J.Biol.Chem., 284:24501-, 2009

PubMed Abstract: The neuroinvasive pathogen Neisseria meningitidis has 13 capsular serogroups, but the majority of disease is caused by only 5 of these. Groups B, C, Y, and W-135 all display a polymeric sialic acid-containing capsule that provides a means for the bacteria to evade the immune response during infection by mimicking host sialic acid-containing cell surface structures. These capsules in serogroups C, Y, and W-135 can be further acetylated by a sialic acid-specific O-acetyltransferase, a modification that correlates with decreased immunoreactivity and increased virulence. In N. meningitidis serogroup Y, the O-acetylation reaction is catalyzed by the enzyme OatWY, which we show has clear specificity toward the serogroup Y capsule ([Glc-(alpha1-->4)-Sia](n)). To understand the underlying molecular basis of this process, we have performed crystallographic analysis of OatWY with bound substrate as well as determined kinetic parameters of the wild type enzyme and active site mutants. The structure of OatWY reveals an intimate homotrimer of left-handed beta-helix motifs that frame a deep active site cleft selective for the polysialic acid-bearing substrate. Within the active site, our structural, kinetic, and mutagenesis data support the role of two conserved residues in the catalytic mechanism (His-121 and Trp-145) and further highlight a significant movement of Tyr-171 that blocks the active site of the enzyme in its native form. Collectively, our results reveal the first structural features of a bacterial sialic acid O-acetyltransferase and provide significant new insight into its catalytic mechanism and specificity for the capsular polysaccharide of serogroup Y meningococci.

PubMed: 19525232
DOI: 10.1074/JBC.M109.006049

実験手法

X-RAY DIFFRACTION (1.95 Å)